In a fixture that has in the past become title deciders, Manchester United vs Arsenal in recent times has proved to be a tough assignment for Arsene Wenger's team. With the humiliating 8-2 defeat at the hands of the Red Devils still ringing in their ears two years down the line, Gunners fans will rightly be sceptical about the trip to Old Trafford on Sunday afternoon. The North London side are league leaders at the moment, five points clear of Chelsea after 10 games played, but still the club's fans refuse to be drawn on their title chances. Even a week that began with a 2-0 victory over Liverpool and a sensational midweek win in Dortmund in the Champions League has not won over some. Their week will end in Manchester this Sunday, and based on previous results against the champions they have a right to be doubtful. The Gunners have only lost one league game, a shock 3-1 defeat to Aston Villa at the Emirates Stadium on the first day of the season, but things have to come to an end sometime, and no one knows this better than a Gooner. In light of this we have compiled a list of 5 reasons why their one and only defeat of the season will be added to at Old Trafford.